Odometer fraud is a serious problem affecting the used vehicle sales industry, because used vehicle prices are determined by the age, mileage, and overall condition of the vehicle. Of these factors, the age and mileage have the greatest effect on the price of the used vehicle. There is little way to falsify the age of the vehicle, however, because the vehicle identification number (VIN) tag permanently attached to the vehicle indicates the model year of the vehicle. Accordingly, the most common way to fraudulently inflate the value of the vehicle is to modify the odometer reading, so that the odometer mileage appears lower than the actual mileage of the vehicle.
In some cases, odometers are made from a series of rotating dials. However, a person can modify the reading on such a mechanical odometer by “roll back”, in which the number dials are rotated in reverse to show a lower mileage number. Various techniques have been developed to prevent these modifications. One way to counteract this type of odometer fraud is to employ a digital odometer, which is not subject to roll back.
A digital odometer is typically connected to a sensor system, typically located in the engine or tire, that measures a series of vehicle speed pulses generated, for example, from the rotation of the wheel. The sensor system translates the received pulses to a distance value that is displayed on the digital odometer, for example, in miles or kilometers. The pulses can also be used for determining and displaying the vehicle speed on a digital speedometer.
Even digital odometers are susceptible to tampering. Therefore, there is a need for preventing odometer fraud for digital odometers.